LT1424-9_15 Datasheet, PDF (1/16 Pages) Linear Technology – Isolated Flyback Switching Regulator with 9V Output

LT1424-9
Isolated Flyback
Switching Regulator
with 9V Output
FEATURES
s _{No Transformer “Third Winding” or Optoisolator}
Required
s _{Application Circuit Meets PCMCIA Type II}
Height Requirement
s _{Fixed, Application Specific 9V Output Voltage}
s _{Regulation Maintained Well into Discontinuous}
Mode (Light Load)
s _{Load Compensation Provides Excellent}
Load Regulation
s _{Available in 8-Pin PDIP and SO Packages}
s _{Operating Frequency: 285kHz}
U
APPLICATIO S
s _{Ethernet Isolated 5V to – 9V Converter}
DESCRIPTIO
The LT^®1424-9 is a monolithic high power switching
regulator specifically designed for the isolated flyback
topology. No “third winding” or optoisolator is required;
the integrated circuit senses the isolated output voltage
directly from the primary side flyback waveform. A high
current, high efficiency switch is included on the die along
with all oscillator, control and protection circuitry.
The LT1424-9 operates with input supply voltages from
3V to 20V and draws only 7mA quiescent current. It can
deliver up to 200mA at 9V with no external power devices.
By utilizing current mode switching techniques, it pro-
vides excellent AC and DC line regulation.
The LT1424-9 has a number of features not found on other
switching regulator ICs. Its unique control circuitry can
maintain regulation well into discontinuous mode. Load
compensation circuitry allows for improved load regula-
tion. An externally activated shutdown mode reduces total
supply current to 20µA typical for standby operation.
, LTC and LT are registered trademarks of Linear Technology Corporation.
TYPICAL APPLICATIO
5V
INPUT
COM
– 9V PCMCIA Type II Isolated LAN Supply
(2.41mm Maximum Component Height)
C1
10µF
25V
C2
10µF
25V
100k
1000pF
0.1µF
47pF
LT1424-9
2
V_C
1
SHDN
3 _SYNC
4 _SGND
8
R_CCOMP
7
V_IN
6
V_SW
5
PGND
ISOLATION
BARRIER
C6
R2 _220pF
75Ω
D1
R1
MBRS130LT3
1N5248
75Ω
OUT
COM
C5
220pF
1
3
C3
C4
1.8k
D2
MBR0540T4
T1
10µF
10µF
25V
25V
2
4
– 9V
200mA
1:1
1424 TA01
0.1µF
C1, C2, C3, C4: MARCON THCS50E1E106Z CERAMIC
CAPACITOR, SIZE 1812. [phone]
T1: COILTRONICS CTX02-13483
sn14249 14249fs
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